Dynamic detection of LAN network protocol

ABSTRACT

A method and apparatus for multi-protocol LAN support, which is applicable to Ethernet, Token-Ring, and Asynchronous Transfer Mode (ATM) protocols. The LAN support is located at a workstation and provides for automatic determination of the LAN protocol type and speed. A common adapter card is provided for use in the workstation to interface the workstation to any of the LANs of interest. A four-step sequential process is taught for determining the protocol type and speed.

FIELD OF THE INVENTION

[0001] The present invention relates to the field of computernetworking, specifically to the field of local area networks usingEthernet, Token-Ring, or Asynchronous Transfer Mode protocols.

BACKGROUND OF THE INVENTION

[0002] The present invention is an adapter card for a workstation orpersonal computer for receiving any of the Ethernet, Token-Ring, orAsynchronous Transfer Mode (ATM) protocols, and automaticallydetermining which protocol is presently active and the speed at which itis operating.

[0003] Historically, numerous protocols have evolved for local areanetworks (LANs). Three of the most popular protocols are Ethernet,Token-Ring, or Asynchronous Transfer Mode (ATM). The diversity ofprotocols has created a problem for manufacturers of electronicequipment, such as computers, file servers, hubs, printers, and likeequipments that connect to LANs. The problem is how to build hardware toattach workstations to the local area networks that is compatible with aplurality of protocols. In recent years, the problem has been furthercomplicated by the introduction of a second higher performing versionsof the Ethernet, Token-Ring, or Asynchronous Transfer Mode protocols.Ethernet now operates at 10 MHz rates (called 10Base-T) and 100 MHzrates (called 100Base-TX), Token-Ring operates at either 4 or 16 MHzrates, and ATM operates at either 25 or 155 MHz rates.

[0004] One simple solution to the problem, which has been implemented inthe prior art, is to manufacture a different pluggable card type tosupport each of the different network protocols and speeds. The userwould buy the type of pluggable card required to interface with thenetwork protocol that was available in his office or building. This isnot an ideal solution, because the vendor requires more developmentfunds and a larger inventory of parts, while the user buys an inflexiblesolution and also requires a larger inventory of parts. The industry hasevolved to more flexible solutions using a single card type that hasautomatic detection of the protocol type and speed. This is possible,because a standardized connector has evolved which requires theprotocols of interest to be standardized to the same physical connectorcalled RJ-45. FIG. 1 shows the RJ-45 contact assignments and how theydiffer for the protocols of interest.

[0005] In U.S. Pat. No. 5,574,722, “Protocol Independent Switch” bySlykhouse et al., Slykhouse teaches a method for automaticallydetermining the network protocol, either Token-Ring or Ethernet, for anetwork hub or concentrator. Slykhouse uses the RJ-45 pin connections asshown in FIG. 1 and teaches hardware for listening for a frame onspecific pins to differentiate between Token Ring or Ethernet. Thepresent invention uses the RJ-45 pins to help in the automaticdetermination of the LAN protocol being used but, in addition, requiresrecognizing the media access control (MAC) layer protocol differences.The present invention requires a more complex mechanism for automaticprotocol determination because of the additional ATM protocol andadditional speed selections allowable for Ethernet and ATM. The presentinvention is not an obvious extension of Slykhouse's method but involvesmedia speed/encoding detection hardware and active transmission of testframes which loopback to the sender and are non-intrusive in nature.This is vastly different than Slykhouse's passive listening method. Thepresent invention also differs from Slykhouse in the field ofapplication. Slykhouse provides a method for network protocol detectionin the networking infrastructure device (hub or concentrator), while thepresent invention is for an adapter card in a workstation.

[0006] In U.S. Pat. No. 5,249,183, “Interfacing Unit for Local AreaNetworks” by Wong et al., Wong teaches a mechanism for an Ethernetadapter to provide attachment to a traditional Ethernet coaxial networkor an Ethernet twisted pair (10Base-T) network. The adapterautomatically selects the network that is active by first checking foractivity on the 10Base-T network by sensing the presence of linkintegrity pulses. If the 10Base-T network is inactive, it then uses thecoaxial network. The approach for detecting Ethernet activity (presenceof link integrity pulses) is the same listening approach used in thepresent invention. Detection allows the adapter to select theappropriate Ethernet media to use. However, Wong applies only toselection of the appropriate physical media specifically for an Ethernetnetwork, whereas the present invention applies to selection of theappropriate protocol used by the network, that of Token-Ring, Ethernet,or ATM.

[0007] Wong's method is passive, but the present invention involvesmedia speed/encoding detection hardware and active transmission of testframes which loop back to the sender and are non-intrusive in nature.

[0008] In U.S. Pat. No. 5,142,528, “Protocol Selector and ProtocolSelection Method” by Kobayashi et. al., Kobayashi teaches a mechanismfor two stations which support multiple protocols to negotiate theprotocol to be used. Generically, this is accomplished through the useof an independent communication port over which the protocol to be usedby the primary communication port is negotiated. Kobayashi also teachesthe specific case of negotiating B channel protocols over the D channelof an Integrated Services Digital Network (ISDN) link. This does notrelate to the present invention in that no independent communicationchannel exists for determining or negotiating the protocol used by theprimary channel. The present invention deals with determining theoperational protocol of a LAN network in a non-disruptive manner andthen attaching to the network. Negotiation of the operating protocol isnot part of the process.

[0009] In U.S. Pat. No. 5,497,460, “System and Method for DeterminingNetwork Connectivity” by Bailey et al., Bailey teaches a mechanism forproviding automated detection of the LAN protocol for a networkinterface card in a workstation that supports multiple protocols. Theautomated detection mechanism in the workstation detects the protocolutilized by the networking infrastructure device to which theworkstation is attached. This is the same problem solved by the presentinvention. Bailey's method differs in that the process proposed byBailey can be disruptive, and the present invention is non-disruptive.Bailey detects the protocol by sending a logical link control (“LLC”)frame—which is a potentially disruptive process. The present inventiondoes not send any frames which may be disruptive during the protocoldetection process. In addition, the transmission of LLC frames proposedby Bailey is applicable only to Ethernet and Token-Ring but not for ATM.The present invention provides detection for Ethernet, Token-Ring, andATM.

[0010] In U.S. Pat. No. 5,442,629, Token Ring Speed Detector” by Geyeret al., Geyer teaches a method and apparatus for determining LAN speedfor Token-Ring LANs by choosing between the two standard Token-Ringspeeds: 4 MHz and 16 MHz. Geyer's method applies only to Token-Ring.Geyer's teachings are applicable to the present invention in thatGeyer's method is used directly to supplement the present invention bydetermining at what speed the Token-Ring is operating after the presentinvention determines that the connected LAN is Token-Ring. Geyer differsfrom the present invention in that it does not provide automaticdetermination of the LAN type from amongst three candidates: Ethernet,Token-Ring, and ATM.

[0011] In U.S. Pat. No. 5,530,842, “Generic Backplane System Which IsConfigurable to Serve Different Network Access Methods Simultaneously”by Abraham et al., Abraham teaches a mechanism for supporting multipleprotocols over a generic backplane of a communications hub orconcentrator. Separate modules, which are protocol and physical networkspecific, are still provided for attaching to the appropriate LANnetwork. Abraham's invention is specific to the implementation of a hubbackplane which, in essence, is a proprietary LAN network. It does notspecifically address the attached protocols, i.e., protocols can betranslated or encapsulated within the backplane network of Abraham. Thebackplane network must carry all protocols of the attaching networks, itdoes not need to specifically and completely conform to any one of thenetworks. The present invention is for devices attaching to standard LANnetworks where the attaching device must specifically and completelyconform to the attaching network, and the present invention provides themechanism for doing so.

[0012] In IBM Technical Disclosure Bulletin, Vol 29, No 2,. July 1986,the article, “Method to Establish a Network Connection Dynamically,”teaches a method of connection setup at the Network Layer of theprotocols. The article applies to a different protocol layer and has norelation to the present invention which addresses LAN operation at theMAC and physical (PHY) layers.

[0013] In IBM Technical Disclosure Bulletin Vol. 29, No. 9, February1987, the article “ECL Reconfiguration Using a Circuit Switch,” teachesa method for configuring switches for internal port to port connections.It does not provide for the configuration of protocols. It is thereforenot related to the present invention but applies to the configuration ofLAN hardware.

[0014] In U.S. Pat. No. 5,568,525, “System and Method for Connection ofMultiple Protocol Terminals” by de Nijs et al., de Nijs teaches amechanism for automated network configuration. De Nijs differs from thepresent invention in that de Nijs provides network configuration at thenetworking infrastructure device. The present invention provides networkconfiguration at the user workstation. In addition, de Nijs uses amechanism of detection of protocol based on characteristic impedance ofthe transmission media. This is different from the present invention'sdetection mechanism, which is based on PHY/MAC layer of Ethernet,Token-Ring, and ATM.

[0015] In U.S. Pat. No. 5,586,117, “Method and Apparatus Which AllowsDevices with Multiple Protocol Capabilities to Configure to a CommonProtocol Configuration” by Edem et al., Edem teaches an automaticdetermination method for Ethernet only to distinguish between the 10 and100 MHz versions. Edem teaches a scheme using clock pulses to matchconfigurations between a workstation and a network infrastructuredevice. Edem's method differs from the present invention in that it doesnot provide a mechanism to distinguish between differing LAN protocols.

[0016] In European Patent 577,435 A1, “Common Interface for aCommunication Network” by Hutchison et al., Hutchison teaches a commoninterface for Ethernet only. Hutchison teaches a mechanism todistinguish between Ethernet interfaces-Attachment Unit Interface (AUI)or 10Base-T. Hutchison differs from the present invention in thatHutchison does not provide a mechanism to distinguish between differingLAN protocols.

[0017] Japanese Publication 06-085848 teaches the detection of 10Base-TEthernet vs. Integrated Services Digital Networks (ISDNs). The schemetaught in the publication is to use a filter to distinguish the signalfrequency (10 Mb vs. 56 Kb). The Japanese publication differs from thepresent invention in that it does not use pin assignments or protocolinformation. The Japanese publication also differs from the presentinvention in that it does not consider Token-Ring or ATM.

[0018] It is a further object of this invention to provide a LAN adapterthat detects whether the network connection of a workstation isEthernet, Token-Ring, or ATM, and adapts automatically to the type andspeed of the attached network.

[0019] It is a further object of this invention to provide protocol typeand speed detection using active transmission of test frames on anon-disruptive basis that does not affect the operation of the networkin relation to other attachments during the protocol search process.

[0020] It is an object of this invention to provide a single apparatusfor the support of multiple LAN protocols where several different speedsoptions are supported for each of the multiple protocols and that thisdetection occurs in an optimal sequence (i.e., most likely conditionsare detected first in order to minimize setup time for the user).

SUMMARY OF THE INVENTION

[0021] In accordance with the invention, a method and apparatus isprovided for multi-protocol LAN support, which is applicable toEthernet, Token-Ring, and Asynchronous Transfer Mode (ATM) protocols.The LAN support is located at a workstation or personal computer andprovides for automatic determination of the LAN protocol type and speed.A standard connector called RJ-45 is used to connect the workstation tothe LAN, regardless of the LAN protocol. All of the LANs of interest usethe RJ-45 connector but use different contact assignments as shown inFIG. 1.

[0022] An adapter card is provided for use in the workstation tointerface the workstation to any of the LANs of interest. The card usesthe RJ-45 connector to interface to the LAN and contains circuitry toadapt the LAN to the workstation's input/output (I/O) bus. A single LANhaving one of the protocols of interest (Ethernet, Token Ring, or ATM)is attached via the RJ-45 connector and the adapter card willautomatically detect the LAN type and respond to it. In addition, theadapter detects and supports one or more speeds for each LAN type. Forexample, the adapter could be structured to support two different speedsfor each LAN type as follows: Ethernet operating at 10 MHz rates (called10Base-T) and 100 MHz rates (called 100Base-TX), Token Ring operating ateither 4 or 16 MHz rates, and ATM operating at either 25.6 or 155 MHzrates. The speeds used in this example are used throughout thisdisclosure, but other speeds which are defined using the RJ-45 connectorwith the same pin assignments are within the scope of the invention.

[0023] The automatic determination of LAN type and speed is accomplishedusing four sequential steps, with each step providing a unique function.A summary of the four steps is as follows:

[0024] Step 1—Ethernet Detection: The Ethernet network will always havedetectable activity on the receive line within a maximum time period of24 ms. RJ-45 contact assignments guarantee that a Token Ring or ATMnetwork do not cause activity on the RJ-45 3/6 pair. Therefore, activityon this pair indicates an operational Ethernet network. Once determinedto be Ethernet, the adapter will send messages on the transmit link todifferentiate between 10Base-T or 100Base-TX operation.

[0025] Step 2—Token-Ring Detection: The adapter transmits and detectsthe reception of a loopback message at 16 Mbps over the RJ-45 contactsassigned for Token-Ring. If the loopback message returns to theworkstation, then the protocol must be Token-Ring. Once determined to beToken-Ring, the normal ring speed listen protocol will determine thecorrect data rate.

[0026] STEP 3—ATM Detection: The process of determining ATM-25 orATM-155 first involves listening for both media speeds. First, theadapter sets the transceiver for media speed 155 Mbps and listens(receives frames from the network). If properly framed idle cells arereceived, then the link is ATM-155. If an ATM-155 link is not detected,then the transceiver is set for media speed 25.6 Mbps and the adapterlistens. If properly decoded idle characters are received, then the linkis ATM-25. If neither listening attempt indicated the ATM media speed,then the workstation adapter will attempt transmission of idlecharacters at both speeds. If the workstation detects a valid signalbeing returned, then ATM connection of the associated speed isdetermined. Transmitting on an ATM link to determine the line speed isnon-disruptive to the network because ATM is a point-to-point switchednetwork.

[0027] STEP 4: No LAN Detected: In the event that the first three stepshave failed to determine the network protocol, then the workstationdetects an error event and makes appropriate notification to the user.

[0028] The network adapter of the present invention is provided aseither a planar embedded function of the workstation or as networkinterface card which is mounted on the adapter card.

[0029] The advantages of this invention will become apparent from thefollowing detailed description of the presently preferred embodiments ofthe invention, taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0030]FIG. 1 is a table showing the contact assignment differences forthe standard RJ-45 connector when connecting to Ethernet, Token-Ring, orATM according to the prior art.

[0031]FIG. 2 is a diagram showing the topology of the standard LANnetwork and the automatic determination decision of the active LANprotocol type as made by the network interface card of the workstationaccording to the preferred embodiments of this invention.

[0032]FIG. 3 is a diagram showing the topology of the standard LANnetwork and the connection to three workstations, wherein eachworkstation connects to a different LAN protocol and each has a networkinterface card implementing the automatic determination method accordingto the preferred embodiments of this invention.

[0033]FIG. 4 is a flow chart showing the details of the protocol typeand speed selection algorithm according to the preferred embodiment ofthis invention.

[0034]FIG. 5 is a block diagram showing the typical implementation ofthe network interface adapter function according to the prior art.

[0035]FIG. 6 is a diagram showing a first functional implementation ofthe network interface adapter card for determining the protocol type andspeed of the LAN connected to the workstation according to theembodiment of this invention.

[0036]FIG. 7 is a diagram showing a second functional implementation ofthe generic network interface adapter card for determining the protocoltype and speed of the LAN connected to the workstation according to thepreferred embodiment of this invention.

[0037]FIG. 8 is a diagram showing an alternative functionalimplementation of the network interface adapter for determining theprotocol type and speed using a chip mounted on the processor planaraccording to the embodiment of this invention.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT OF THE INVENTION

[0038] In accordance with the invention, a method and apparatus isprovided for multi-protocol LAN support, which is applicable toEthernet, Token-Ring, and Asynchronous Transfer Mode (ATM) protocols.Referring to FIG. 2, a typical LAN network 100 is shown that has theend-stations 205 (workstations) attached to wall-outlets 140 in eachoffice. The wall-outlets 140 provide a connector for attachingend-stations 205 to a LAN link that has wire or cable laid throughout abuilding, for instance, in the walls, floor, or ceiling. Thewall-outlets 140 are each connected to a port of network 100 and tonetwork interface card (NIC) 200 via links 147. NIC 200 receives andtransmits messages configured in frames to network 100. The interfaceprovided by network 100 to NIC 200 is any of the three most popularLANs, which are Ethernet, Token-Ring, or ATM.

[0039] NIC 200 is a LAN adapter card which is plugged into an adaptercard slot in workstation 205. NIC 200 automatically detects whether theNIC 200 is connected to Ethernet, Token-Ring, or ATM. NIC 200 providesLAN support with automatic determination of the LAN protocol type andspeed, i.e., wall outlet 140 can be attached to Ethernet 110, Token-Ring120, or ATM 130 and NIC 200 will automatically determine which one ofthe LANs 110, 120, 130 is active. NIC 200 responds only to the oneactive LAN type 110, 120, 130. FIG. 2 shows three wall outlets 140 eachattached to a different LAN 110, 120, 130; the meaning here is that eachwall outlet 140 attaches to one and only one LAN type 110, 120, 130. Thequestion marks 145 indicate that NIC 200 questions the type of LAN 110,120, 130 to which it is attached and automatically determines the LANsupport required from the three LAN candidate types 110, 120, 130. FIG.2 does NOT mean that NIC 200 and workstation 205 attach simultaneous tothree wall outlets 140, nor does a single NIC 200 simultaneouslycommunicate with all three LANs 110, 120, 130. FIG. 2 is meant to showthat NIC 200 and workstation 205 attach to any one of the LANs 110, 120,130, and nothing more.

[0040] Referring to FIG. 3, normal LAN to end-station attachments areshown, where each wall outlet 140 connects to a different copy of NIC200 incorporated into different workstations 205 a, 205 b, and 205 c.The same LAN adapter card type 200 is used in each workstation 205, suchthat NIC 205 a automatically configures itself to communicate withEthernet 110, NIC 205 b automatically configures itself to communicatewith Token-Ring 120, and NIC 205 c automatically configures itself tocommunicate with ATM 130.

[0041] Wall outlets 140 are implemented using a standard connectorcalled RJ-45 which is used to connect the workstation 205 to the LAN110, 120, 130, regardless of the LAN protocol. All of the LANs ofinterest use the RJ-45 connector but use different contact assignmentsas shown in FIG. 1. For instance, a Token-Ring 120 operating at either 4or 16 MHz uses contacts 3 and 6 (3/6) to support transmission of framesto the network 100, and contacts 4 and 5 (4/5) to support the receivingof frames from network 100. In contrast, ATM 130 uses contacts 1 and 2(1/2) to support transmission of frames to the network 100, and contacts7 and 8 (7/8) to support the receiving of frames from network 100.Ethernet 110 uses contacts 1 and 2 (1/2) to support transmission offrames to the network 100, and contacts 3 and 6 (3/6) to support thereceiving of frames from network 100. The Ethernet contacts are definedin ISO/IEC 8802-3:1996. The Token-Ring contacts are defined in ISO/IEC8802-5:1995. The ATM contacts are defined in the ATM Forumspecification, “Physical Interface Specification for 25.6 Mb/s overTwisted Pair Cable,” af-phy0040.000, Nov. 7, 1995, and “ATM PhysicalMedium Dependent Interface Specification for 155 Mb/s over Twisted PairCable,” af-phy0015.000, September, 1994.

[0042] Referring to FIG. 4, the algorithm or logic process used by NIC200 to detect the active LAN protocol type is shown. The logic providesfor a non-disruptive detection of the LAN protocol by carefully orderingthe protocol detection steps. First, the adapter tests for Ethernet bylistening on the appropriate RJ-45 contacts. If Ethernet is notdetected, the adapter tests for Token-Ring using the loopback testdefined in the IEEE 802.5 Token-Ring standard. Finally, havingdetermined that the LAN segment is not Ethernet or Token-Ring, theadapter tests for ATM-25 and then ATM-155. The test for ATM is first tolisten, and then to transmit. The logic provides for positive detectionof the LAN protocol. If none of the tests is successful, then the LANprotocol is unknown or the cable is not attached to the network.

[0043] In accordance with the invention, the automatic determination ofthe LAN type and speed is accomplished using four sequential steps witheach step providing a unique function. The four steps are as follows:

[0044] Step 1—Ethernet Detection: The Ethernet network will always havedetectable activity on the receive contacts 3/6 of FIG. 1 within amaximum time period of 24 ms. RJ-45 contact assignments guarantee that aToken Ring or ATM network do not cause activity on the RJ-45 3/6 pair.Therefore, activity on the 3/6 pair indicates an operational Ethernetnetwork. The activity is comprised of either data frames beingtransmitted or link test pulses (LTP) being sent in the absence of datatransmission. For Ethernet, a physical layer function called the MAU(Medium Attachment Unit) monitors for link integrity by sending a linktest pulse (LTP) in the absence of received data. The MAU function for100-TX extends this capability by using a compatible fast link pulse(FLP) to provide an auto-negotiation of 10/100 function in addition tothe link integrity function.

[0045] Referring to FIG. 4, the detailed decision sequence associatedwith step 1 is shown to include flow chart entities 300 to 308. Thesequence starts with entity 300. In block 302, the transceiver fornetwork link 147 of FIG. 2 is set to either Ethernet (ENET) speed—10 or100 Mbps. NIC 200 then listens on the 3/6 contact pair of the RJ-45connector for (data) activity or the LTP as shown in block 304. NIC 200determines if a signal is detected on the 3/6 contact pair as shown byblock 306. NIC 200 is in listen mode and does not transmit any dataframes or LTPs. The same listening procedure 304, 306 is used for eitherof the Ethernet speeds: 10 or 100 MHz. If (data) activity or LTPs aredetected, the unknown LAN type 110, 120, 130 is determined to be ENET 10or 100. Once the LAN is determined to be Ethernet 110, the NIC 200 willsend FLP messages on the transmit link to negotiate between 10Base-T or100Base-TX operation as shown by block 308. The auto-negotiationprocedure is defined in IEEE Std 802.3u-1995 “Media Access Control (MAC)Parameters, Physical Layer, Medium Attachment Units, and Repeater for100 Mb/s Operation, Type 100 BASE-T,” in clause 28.

[0046] If there is no signal detection on the 3/6 contact pair, thenetwork is determined not to be Ethernet 110, and Step 2 (flow chartentities 310 to 316) is invoked.

[0047] Although the Ethernet detection step has been described withreference to Ethernet speeds of 10 or 100 Mbps, other speeds that aredefined using an RJ-45 connector and the same contact assignments arepossible and within the scope of the invention.

[0048] Step 2—Token-Ring Detection: Step 2 includes flow chart entities310 to 316. If the LAN segment is Token-Ring, NIC 200 will not receiveany frames initially unless it sends messages to itself. NIC 200 issuesa loopback test, i.e., transmits a frame to network 100 over the 3/6contact pair of the RJ-45 connector, which traverses the network and isaddressed to return to the same RJ-45 connector over the receivingcontact pair 4/5. If the loop-back message returns to the workstation,then the protocol must be Token-Ring. This is guaranteed since theToken-Ring RJ-45 contacts 4/5 for receive are not used fortransmit/receive in ATM. Note that it is first required to verify thatthe LAN is NOT Ethernet prior to a loop-back test for Token Ring,because if the transmission of the loop-back message is on what isactually an Ethernet network it would disrupt that network. Also notethat ATM verification is not yet required because contact assignmentsfor Token Ring and ATM are mutually exclusive such that there is nodisruption if the actual network is ATM.

[0049] NIC 200 transmits and detects the reception of loopback messagesby transmitting one speed at a time over the Token-Ring RJ-45 contacts3/6 and listening for a return on contacts 4/5. Referring to FIG. 4, inblock 310 the transceiver for network link 147 of FIG. 2 is set toToken-Ring (T/R) speed: 16 Mbps. Loopback messages are transmitted overcontact pair 3/6 by NIC 200 as shown by block 312. NIC 200 checks forthe reception of loopback messages. If the loopback message returnssuccessfully, block 314 selects block 316 to be executed next. Block 316performs ring insertion and auto-speed detection to determine if theToken-Ring speed is 4 or 16 Mbps. The detection method for determiningthe Token-Ring media speed is not unique to the present invention. Thedetection method is disclosed by U.S. Pat. No. 5,442,629, “Token RingSpeed Detector” by Geyer et al., and is used directly for theimplementation of block 316. The detection method is well documented,and the details are not included herein.

[0050] If the loopback messages transmitted by the workstation are NOTreceived by that workstation, then the LAN segment is NOT an operationalToken Ring. Block 314 selects to go to Step 3.

[0051] Although the Token Ring detection step has been described withreference to speeds of 4 or 16 Mbps, other speeds that are defined usingan RJ-45 connector and the same contact assignments are possible andwithin the scope of the invention.

[0052] STEP 3—ATM Detection: Step 3 includes flow chart entities 318 to350. For ATM, it is possible for other ports on the ATM LAN to be in thereceive-only state when the link is idle, which is a valid mode ofoperation. Thus, the process of determining ATM-25 or ATM-155 involvesboth listening and active transmission. The process of determining anATM LAN first involves listening for both media speeds. The order of thelistening events can be ATM-25 and then ATM-155 or ATM-155 and thenATM-25, and the procedure described in this section will still detectthe appropriate protocol media speed. Referring to FIG. 4, NIC 200 firstsets the transceiver for media speed 155 Mbps, as shown by block 318,and listens for frames arriving on the RJ-45 connector contacts 7/8 asshown by block 320. If properly framed idle cells are received, thenblock 322 detects that the LAN is ATM-155 as shown by block 324. If anATM-155 link is not detected, then block 322 selects block 326, and thetransceiver is set for media speed 25.6 Mbps, and the adapter listens onthe RJ-45 connector contacts 7/8 as shown by block 328. If properlyframed idle characters are received as detected by block 330, then theLAN is ATM-25 as shown by block 332.

[0053] If neither listening attempt for ATM indicated the ATM mediaspeed, then NIC 200 transmits idle characters to network 100 in case theLAN is ATM and the other ports are in the receive-only state. This willprovide detectable activity if the LAN is ATM. At this point, block 330controls the further testing by selecting block 333. The transceiver isset for media speed 25.6 Mbps as shown by block 333. NIC 200 transmitsidle characters to network 100 on the RJ-45 connector contacts at 1/2 asshown by block 334. NIC 200 then listens for a valid signal on the RJ-45connector contacts 7/8 as shown by block 336. If NIC 200 detects a validsignal as shown by block 338, then ATM connection is determined to beATM-25 as shown by block 340. If NIC 200 does NOT detect a valid signalas shown by block 338, block 342 is selected next.

[0054] The transceiver is set for media speed 155 Mbps as shown by block342. NIC 200 transmits idle characters to network 100 on the RJ-45connector contacts 1/2 as shown by block 344. NIC 200 then listens for avalid signal on the RJ-45 connector contacts 7/8 as shown by block 346.If NIC 200 detects a valid signal as shown by block 348, then ATMconnection is determined to be ATM-155 as shown by block 350. If NIC 200does NOT detect a valid signal as shown by block 348, a failure isdetected as none of the LANs of interest were found to be connected toNIC 200.

[0055] Transmitting on an ATM link 147 to determine the line speed isnon-disruptive to the network 100, because ATM is a point-to-pointswitched network. For instance, Token-Ring is a loop connection whereall end-stations 205 are connected to the loop. Any frame sent over theToken-Ring must traverse the intermediate end-stations to get to thedesired destination. However, ATM does not interconnect in a loop but isswitched directly from the transmitter to the receiver without havingthe message pass through other end-stations. Therefore, transmitting onATM is not disruptive to the other end-stations.

[0056] The order of the transmission attempts (ATM-25 and then ATM-155)could be reverse, and the procedure described herein as step 3 wouldstill operate correctly and determine the proper LAN type and speed.

[0057] Although the ATM detection step has been described with referenceto ATM speeds of 155 or 25.6 Mbps, other speeds that are defined usingan RJ-45 connector and the same contact assignments are possible andwithin the scope of the invention.

[0058] STEP 4: No LAN Detected: In the event that steps 1, 2, and 3 failto determine the network 100 protocol, then NIC 200 detects an errorevent and makes appropriate notification to the user as shown by block352 of FIG. 4. The error event can occur due to a failure conditionwhich may be either permanent or transient. NIC 200 declares the failureto the user, and at the option of the user NIC 200 may be commanded toretry the protocol detection process beginning from block 300.

[0059] Network Interface Card Description: The Network Interface Card(NIC) 200 uses the RJ-45 connector to interface to the LAN 100 andcontains circuitry to adapt the LAN to the workstation's input/output(I/O) bus. A single LAN having one of the protocols of interest(Ethernet, Token Ring, or ATM) is attached via the RJ-45 connector andthe adapter card 200 will automatically detect the LAN type 110, 120,130 and respond to it. In addition the adapter card 200 detects andsupports two different speeds for each LAN type.

[0060] In general, low cost NICs generally are integrated into a singlechip and organized as shown in FIG. 5. NIC 200 resides in workstation205, which is further comprised of processor 290 and system memory 295.NIC 200 has two interfaces, one to the workstation system 290, 295 andone to network 100. For workstation 205 communications to adapter 200,NIC 200 interfaces with processor 290 and system memory 295 via systembus 292, which is usually the PCI bus. Bus interface connector 210 isused to connect NIC 200 to bus 292, and bus master interface 212controls the NIC interface to bus 292 by moving data to and from systemmemory 295. FIFO storage 234 is used for intermediate data storage andspeed matching of bus 292 to the network 100. Buffer management 233 isused for managing the data flow between system memory 295 and FIFOstorage 234, as the data flows through bus master interface 212. Statusand control section 235 provides the hardware control interface for thesoftware device driver running on processor 290.

[0061] The NIC 200 interface to network 100 is comprised of media accesslayer 236 which runs the network protocol and the physical transceiver238 which is the line driver and receiver to interface to network 100.Physical transceiver 238 is connected to network 100 throughtransformers and other electrical components and connector block 270which includes the RJ-45 connector described in FIG. 1. Most NICs todayconsist of a single chip device of this type mounted on a PC card with aconnector for the host bus 210 and a connector 270 for the networkinterface. The NIC 200 shown in FIG. 5 is consistent with the prior art,where one NIC 200 interfaces to one LAN type 110, 120, 130. Threedifferent cards are required, one card to interface with each of thethree LAN types: Ethernet, Token-Ring, and ATM. The three differentcards would each contain identical bus connector 210 blocks, bus masterinterface 212 blocks, FIFO storage 234 blocks, and magnetics andconnector 260 blocks. However, each of the three card types wouldcontain different buffer management 233 blocks, Status & control 235blocks, media access control 236 blocks, and physical transceiver 238blocks to tailor its operation to one of the LANs: Ethernet, Token-Ring,or ATM.

[0062] In contrast, FIG. 6 shows the first embodiment of the presentinvention where all three of the card types described by FIG. 5 arecombined into a single card 200 d comprised of the automatic protocoldetermination function. The NIC 200 d is a multi-protocol adapter whichcontains independent physical transceivers 248, 258, 268; independentmedia access controls (MAC) 246, 256, 266; independent buffer managementcontrols 243, 253, 263; independent status & control sections 245, 255,265; and independent data movement FIFO storage units 244, 254, 264 forthe Ethernet, Token Ring, and ATM protocols. The protocol selectionlogic 220 performs the logic detailed in FIG. 4. The protocol selectionlogic 220 individually enables the different adapter entities 240, 250,260 in the process of determining the network protocol. With thisimplementation, the protocol selection logic 220 performs moreoperations in parallel, in particular those operations involvinglistening for network activity, such as blocks 304 and 320 of FIG. 4.This allows for quicker determination of the network protocol. However,the NIC 200 d of FIG. 6 has the disadvantage of requiring the high costof providing each of the individual entities 240, 250, and 260.

[0063] Referring to FIG. 7, a more cost effective solution is the secondand preferred embodiment of the present invention, which provides amulti-protocol NIC 200 e with a configurable, pico-processor or statemachine based entities 283, 285. The NIC 200 e contains the same busconnector 210 block, bus master interface 212 block, FIFO storage 234block, and magnetics and connector 270 block as NIC 200 a, 200 b, and200 c. However, pico-processor controlled buffer management 283 is a newconfigurable entity that is capable of doing the same functions providedby all three buffer management entities 243, 253, and 263 of NIC 200 d(FIG. 6). Likewise, pico-processor controlled status & control section285 is a new configurable entity that is capable of doing the samefunctions provided by all three status & control sections 245, 255, and265 of NIC 200 d. The buffer management 283 and status & control 285 areprogrammable entities that are controlled by a pico-processor, such thatblocks 283 and 285 are adaptable to any network specific functionsrequired to support Ethernet, Token-Ring, or ATM networks. NIC 200 e hasindependent entities 246, 256, 266 for each of the MAC protocols, sincethey each have very specific requirements. A common physical transceiver288 is used, as this is considered viable in the state-of-the-arttechnology. The approach works equally well with independent transceiverentities 248, 258, and 268 of FIG. 6 replacing transceiver 288. Theprotocol selection logic 224 performs the four step process detailed inFIG. 4. However, the protocol selection logic of NIC 200 e is slightlydifferent than the protocol selection logic 220 of NIC 200 d (FIG. 6) inthat it does not perform any operations in parallel. Due to the use ofcommon functions for pico-processor controlled entities 283, 285, theprocess must be followed in a sequential manner as shown in FIG. 4.

[0064] The advantage of the present invention is that a common networkinterface adapter card is used to interface to any of the popular LANs:Ethernet, Token-Ring and ATM. The common card has the capability toautomatically determine the type and speed of the LAN to which it isconnected.

[0065] It is a further advantage of this invention that protocol typeand speed detection is provided using active transmission of test frameson a non-disruptive basis that does not affect the operation of thenetwork in relation to other attachments during the protocol searchprocess.

[0066] Alternative Embodiments

[0067] An alternative embodiment of the present invention is to providethe LAN interface determination and function as part of the processorplanar design. A planar is a multi-layer interconnection board used formounting the processor, its memory and associated functions andinterfaces.

[0068] Since the network adapter function implemented in NIC 200 isusually provided as a single chip, it can be mounted on an adapter cardas described hereinbefore, or mounted directly on the processor planaras a planar embedded function of the workstation. Referring to FIG. 8,the workstation planar 291 is shown containing processor 290, systemmemory 295, network adapter 294, other processor support chips or cardslots 297, and RJ-45 connector 296 for interfacing to network 100. Inthis alternate embodiment, no pluggable adapter card 200 is required tointerconnect to network 100. Instead, the network adapter chip 294provides the exact same automatic protocol determination featuresperformed by the NIC 200 for determining the LAN type and speed.

[0069] It will be appreciated that, although specific embodiments of theinvention have been described herein for purposes of illustration,various modifications may be made without departing from the spirit andscope of the invention.

[0070] Accordingly, the scope of protection of this invention is limitedonly by the following claims and their equivalents.

What is claimed is:
 1. A network interface card for interfacing betweena processor system and one of a plurality of local area network (LAN)types and LAN speeds, wherein said network interface card comprises:means for automatically determining the LAN type and LAN speed of a LANto which said network interface card is connected.
 2. The networkinterface card of claim 1, wherein the determined LAN type and LAN speedis automatically selected for subsequent support of data transmission toand from said LAN to which said network interface card is connected. 3.The network interface card of claim 1, wherein said plurality of LANtypes and LAN speeds are comprised of one or more of the following:Ethernet operating at either 10 or 100 MHz rates, Token-Ring operatingat either 4 or 16 MHz rates, and Asynchronous Transfer Mode operating ateither 25.6 or 155 MHz rates.
 4. The network interface card of claim 1,wherein said plurality of LAN types and LAN speeds are comprised of oneor more of the following: Ethernet using RJ-45 connector contacts 1 and2 for transmitting frames to a network and RJ-45 connector contacts 3and 6 for receiving frames from a network, Token-Ring using RJ-45connector contacts 3 and 6 for transmitting frames to a network andRJ-45 connector contacts 4 and 5 for receiving frames from a network,and Asynchronous Transfer Mode using RJ-45 connector contacts 1 and 2for transmitting frames to a network and RJ-45 connector contacts 7 and8 for receiving frames from a network.
 5. The network interface card ofclaim 1, wherein said means for automatically determining the LAN typeand LAN speed is performed on a non-disruptive basis that does notaffect the operation of the LAN.
 6. A network interface card forinterfacing between a processor system and one of a plurality of localarea network (LAN) types and LAN speeds, wherein said network interfacecard comprises: means for automatically determining the LAN type and theLAN speed of a LAN to which said network interface card is connected;means for multi-protocol LAN support; and means for automaticallyadapting the LAN support required for data transmission to conform to anetwork protocol provided by the LAN type and the LAN speed.
 7. Thenetwork interface card of claim 6, wherein said plurality of LAN typesand LAN speeds are comprised of one or more of the following: Ethernetoperating at either 10 or 100 MHz rates, Token-Ring operating at either4 or 16 MHz rates, and Asynchronous Transfer Mode operating at either25.6 or 155 MHz rates.
 8. The network interface card of claim 6, whereinsaid plurality of LAN types and LAN speeds are comprised of one or moreof the following: Ethernet using RJ-45 connector contacts 1 and 2 fortransmitting frames to a network and RJ-45 connector contacts 3 and 6for receiving frames from a network, Token-Ring using RJ-45 connectorcontacts 3 and 6 for transmitting frames to a network and RJ-45connector contacts 4 and 5 for receiving frames from a network, andAsynchronous Transfer Mode using RJ-45 connector contacts 1 and 2 fortransmitting frames to a network and RJ-45 connector contacts 7 and 8for receiving frames from a network.
 9. The network interface card ofclaim 6, wherein said means for automatically determining the LAN typeand the LAN speed is performed on a non-disruptive basis that does notaffect the operation of the LAN.
 10. A network interface card forinterfacing between a processor system and one of a plurality of localarea network (“LAN”) types and LAN speeds, wherein said networkinterface card comprises: a plurality of network support functions; andmeans for determining which said network support functions are selectedbased on a LAN type and a LAN speed of one of the plurality of LAN typesand LAN speeds to which the network interface card is connected.
 11. Thenetwork interface card of claim 10, wherein each network supportfunction comprises: hardware required to interface with said one of theplurality of LAN types and LAN speeds to which the network interfacecard is connected.
 12. The network interface card of claim 10, furthercomprising a pico-processor means for providing programmable support orstate machine for said selected network support functions based on theLAN type and the LAN speed of said one of the plurality of LAN types andLAN speeds to which the network interface card is connected.
 13. Anetwork interface card for interfacing between a processor system andone of a plurality of local area network (“LAN”) types and LAN speeds,comprising: a programmable processor or state machine for supporting aplurality of network protocols; and means for determining which one ofthe plurality of network protocols to select and support based on theLAN type and the LAN speed of said one of the plurality of LAN types andLAN speeds to which the network interface card is connected.
 14. Anetwork interface card for interfacing between a processor system andone of a plurality of local area network (“LAN”) types and LAN speeds,comprising: means for interfacing said processor system to said networkinterface card, comprising a processor bus, a bus connector, and busmaster interface for moving data to and from said processor system; anetwork interfacing means for each of said plurality of LAN types andLAN speeds, the network interfacing means comprising a network protocoland a data transfer format, wherein data is formatted as frames fortransfer over said LAN; a protocol selection means for automaticallydetermining the LAN type and the LAN speed of the LAN to which saidnetwork interface card is connected; an intermediate data storage meansfor speed matching of said processor bus to said LAN for the transfer ofdata frames in either direction between said processor system and saidLAN; a data flow management means for managing the data flow betweensaid processor system and said intermediate data storage means; a statusand control means for enabling said processor system to detect a statusand to control said network interface card; a pico-processor or statemachine means for providing programmable support for said networkprotocol to be supported based on the type and speed of said one of aplurality of LAN types and LAN speeds to which the LAN is connected; aplurality of media access control means, each providing means foradapting and controlling the network protocols for one of said pluralityof LAN types; and a physical connection means for connecting saidnetwork interface card to said one of a plurality of LAN types, thephysical connection means comprising a line driver and receiver andnetwork connector to interface to said network.
 15. The networkinterface card of claim 14, wherein said plurality of LAN types and LANspeeds are comprised of one or more of the following: Ethernet operatingat either 10 or 100 MHz rates, Token-Ring operating at either 4 or 16MHz rates, and Asynchronous Transfer Mode (ATM) operating at either 25.6or 155 MHz rates.
 16. The network interface card of claim 14, whereinsaid plurality of LAN types and LAN speeds are comprised of one or moreof the following: Ethernet using RJ-45 connector contacts 1 and 2 fortransmitting frames to a network and RJ-45 connector contacts 3 and 6for receiving frames from a network, Token-Ring using RJ-45 connectorcontacts 3 and 6 for transmitting frames to a network and RJ-45connector contacts 4 and 5 for receiving frames from a network, andAsynchronous Transfer Mode using RJ-45 connector contacts 1 and 2 fortransmitting frames to a network and RJ-45 connector contacts 7 and 8for receiving frames from a network.
 17. The network interface card ofclaim 14, wherein the protocol selection means further comprises anordered sequence of steps for determining the LAN type and the LAN speedcomprising: an Ethernet protocol detection means for detecting dataframes from said LAN to said network interface card; an Ethernet speeddetection means for detecting either 10 or 100 MHz data transfer ratesfor transferring said data frames; an Ethernet not-found detection meansfor detecting that the LAN to which said network interface card isconnected is not Ethernet; a Token-Ring protocol detection means fortransmitting data frames to said LAN from said network interface cardand detecting the return of same data frames from said LAN to saidnetwork interface card; a Token-Ring speed detection means for detectingeither 4 or 16 MHz data transfer rates for transferring said dataframes; a Token-Ring not-found detection means for detecting that theLAN to which said network interface card is connected is not Token-Ring;a first ATM protocol detection means for detecting data frames from saidnetwork to said network interface card; an ATM speed detection means forsaid first ATM protocol detection means for detecting either 25.6 MHz or155 MHz data transfer rates for transferring said data frames; a secondATM protocol detection means for detecting the connection of an ATMnetwork operating at 25.6 MHz to said network interface card bytransmitting data frames at 25.6 MHz to said LAN from said networkinterface card and detecting the return of valid frame cells from saidLAN to said network interface card; a third ATM protocol detection meansfor detecting the connection of an ATM network operating at 155 MHz tosaid network interface card by transmitting data frames at 155 MHz tosaid LAN from said network interface card and detecting the return ofvalid frame cells from said LAN to said network interface card; an ATMnot-found detection means for determining that the LAN to which saidnetwork interface card is connected is not ATM; and an error reportingmeans for reporting to said processor system that there is no Ethernet,Token-Ring or ATM network connect to said network interface card. 18.The network interface card of claim 14, wherein said protocol selectionmeans is performed on a non-disruptive basis that does not affect theoperation of the LAN.
 19. A process comprising an ordered sequence ofsteps for determining a network type and a network speed comprising: anEthernet protocol detection means for detecting data frames from anetwork to a network interface card connected to the network; anEthernet speed detection means for detecting either 10 or 100 MHz datatransfer rates for transferring said data frames; an Ethernet not-founddetection means for detecting that the network to which said networkinterface card is connected is not Ethernet; a Token-Ring protocoldetection means for transmitting data frames to said network from saidnetwork interface card and detecting the return of same data frames fromsaid network to said network interface card; a Token-Ring speeddetection means for detecting either 4 or 16 MHz data transfer rates fortransferring said data frames; a Token-Ring not-found detection meansfor detecting that the network to which said network interface card isconnected is not Token-Ring; a first ATM protocol detection means fordetecting data frames from said network to said network interface card;an ATM speed detection means for said first ATM protocol detection meansfor detecting either 25.6 MHz or 155 MHz data transfer rates fortransferring said data frames; a second ATM protocol detection means fordetecting the connection of an ATM network operating at 25.6 MHz to saidnetwork interface card by transmitting data frames at 25.6 MHz to saidnetwork from said network interface card and detecting the return ofvalid frame cells from said network to said network interface card; athird ATM protocol detection means for detecting the connection of anATM network operating at 155 MHz to said network interface card bytransmitting data frames at 155 MHz to said network from said networkinterface card and detecting the return of valid frame cells from saidnetwork to said network interface card; an ATM not-found detection meansfor detecting that the network to which said network interface card isconnected is not ATM; and an error reporting means for reporting to saidprocessor system that there is no Ethernet, Token-Ring or ATM networkconnect to said network interface card.
 20. A network interface card forinterfacing between a processor system and one of a plurality of localarea network (“LAN”) types and LAN speeds, comprising: a means forinterfacing said processor system to said network interface card,comprising a processor bus, a bus connector, and bus master interfacefor moving data to and from said processor system; a network interfacingmeans for each of said plurality of LAN types and LAN speeds, thenetwork interfacing means comprising a network protocol and a datatransfer format, wherein data is formatted as frames for transfer oversaid LAN; a protocol selection means for automatically determining theLAN type and LAN speed of the LAN to which said network interface cardis connected; a plurality of intermediate data storage means, each forsupporting one of said plurality of LAN types for speed matching of saidprocessor bus to said LAN for the transfer of data frames in eitherdirection between said processor system and said LAN; a plurality ofdata flow management means, each for supporting one of said plurality ofLAN types for managing the data flow between said processor system andsaid intermediate data storage means; a plurality of status and controlmeans, each for supporting one of said plurality of LAN types forenabling said processor system to detect status and to control saidnetwork interface card; a plurality of media access control means, eachproviding means for adapting and controlling the network protocols forone of said plurality of LAN types; and a plurality of physicalconnection means, each for supporting one of said plurality of LAN typesfor connecting said network interface card to said one of a plurality ofLAN types, each further comprising a line driver and receiver.
 21. Thenetwork interface card of claim 20, wherein said plurality of LAN typesand LAN speeds are comprised of one or more of the following: Ethernetoperating at either 10 or 100 MHz rates, Token-Ring operating at either4 or 16 MHz rates, and Asynchronous Transfer Mode (ATM) operating ateither 25.6 or 155 MHz rates.
 22. The network interface card of claim20, wherein said plurality of LAN types and LAN speeds are comprised ofone or more of the following: Ethernet using RJ-45 connector contacts 1and 2 for transmitting frames to a network and RJ-45 connector contacts3 and 6 for receiving frames from a network, Token-Ring using RJ-45connector contacts 3 and 6 for transmitting frames to a network andRJ-45 connector contacts 4 and 5 for receiving frames from a network,and Asynchronous Transfer Mode using RJ-45 connector contacts 1 and 2for transmitting frames to a network and RJ-45 connector contacts 7 and8 for receiving frames from a network.
 23. The network interface card ofclaim 20, wherein said protocol selection means is performed on anon-disruptive basis that does not affect the operation of the LAN. 24.A multi-layer interconnection planar board for mounting electricalcomponents including a processor system and a network interface systemcomprising: a processor and system memory means; a processor support andcard slot means; a network interface control chip, the network interfacecontrol chip further comprising: a means for interfacing said processorsystem to said network interface card, comprising a processor bus andbus master interface for moving data to and from said processor system;a network interfacing means for each of a plurality of local areanetwork (“LAN”) types and LAN speeds, further comprising a networkprotocol and a data transfer format, wherein data is formatted as framesfor transfer over said LAN; a protocol selection means for automaticallydetermining the LAN type and LAN speed of the LAN to which said networkinterface card is connected; an intermediate data storage means forspeed matching of said processor bus to said LAN for the transfer ofdata frames in either direction between said processor system and saidLAN; a data flow management means for managing the data flow betweensaid processor system and said intermediate data storage means; a statusand control means for enabling said processor system to detect thestatus and to control said network interface card; a pico-processor orstate machine means for providing programmable support for said networkprotocol to be supported based on the LAN type and LAN speed of said oneof a plurality of LAN types and LAN speeds to which the networkinterface card is connected; a plurality of media access control means,each providing means for adapting and controlling the network protocolsfor one of said plurality of LAN types; and a physical connection meansfor connecting said network interface card to said one of a plurality ofLAN types, further comprising a line driver and receiver and networkconnector to interface to said network.
 25. The planar board of claim24, wherein said plurality of LAN types and LAN speeds are comprised ofone or more of the following: Ethernet operating at either 10 or 100 MHzrates, Token-Ring operating at either 4 or 16 MHz rates, andAsynchronous Transfer Mode (ATM) operating at either 25.6 or 155 MHzrates.
 26. The planar board of claim 24, wherein said plurality of LANtypes and LAN speeds are comprised of one or more of the following:Ethernet using RJ-45 connector contacts 1 and 2 for transmitting framesto a network and RJ-45 connector contacts 3 and 6 for receiving framesfrom a network, Token-Ring using RJ-45 connector contacts 3 and 6 fortransmitting frames to a network and RJ-45 connector contacts 4 and 5for receiving frames from a network, and Asynchronous Transfer Modeusing RJ-45 connector contacts 1 and 2 for transmitting frames to anetwork and RJ-45 connector contacts 7 and 8 for receiving frames from anetwork.
 27. The planar board of claim 24, wherein the protocolselection means further comprises an ordered sequence of steps fordetermining the LAN type and LAN speed comprising: an Ethernet protocoldetection means for detecting data frames from said network to saidnetwork interface card; an Ethernet speed detection means for detectingeither 10 or 100 MHz data transfer rates for transferring said dataframes; an Ethernet not-found detection means for detecting that the LANto which said network interface card is connected is not Ethernet; aToken-Ring protocol detection means for transmitting data frames to saidLAN from said network interface card and detecting the return of samedata frames from said network to said network interface card; aToken-Ring speed detection means for detecting either 4 or 16 MHz datatransfer rates for transferring said data frames; a Token-Ring not-founddetection means for detecting that the LAN to which said networkinterface card is connected is not Token-Ring; a first ATM protocoldetection means for detecting data frames from said LAN to said networkinterface card; an ATM speed detection means for said first ATM protocoldetection means for detecting either 25.6 MHz or 155 MHz data transferrates for transferring said data frames; a second ATM protocol detectionmeans for detecting the connection of an ATM network operating at 25.6MHz to said network interface card by transmitting data frames at 25.6MHz to said LAN from said network interface card and detecting thereturn of valid frame cells from said LAN to said network interfacecard; a third ATM protocol detection means for detecting the connectionof an ATM network operating at 155 MHz to said network interface card bytransmitting data frames at 155 MHz to said LAN from said networkinterface card and detecting the return of valid frame cells from saidLAN to said network interface card; an ATM not-found detection means fordetecting that the LAN to which said network interface card is connectedis not ATM; and an error reporting means for reporting to said processorsystem that there is no Ethernet, Token-Ring or ATM network connect tosaid network interface card.
 28. The planar board of claim 24, whereinsaid protocol selection means is performed on a non-disruptive basisthat does not affect the operation of the LAN.